Optical recording medium and information recording method

ABSTRACT

An optical recording medium has a multi-layer structure recording layer structure recording layer portion including plural recording layers provided with tracks for guiding a recording light and being adapted to record data, where recording condition information and recording layer identification information for the recording layers are recorded on the tracks as information signals. Test writing is conducted on a recording layer that is subject to recording to derive a suitable recording condition based on recording condition information that is recorded on the recording layer, and direct recording is conducted according to a direct recording condition.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a U.S. continuation application filed under 35 USC111(a) claiming benefit under 35 USC 120 and 365(c) of PCT applicationJP2004/003398, filed Mar. 15, 2004, which claims priority to JapanesePatent Application Serial No. 2003-083619 filed on Mar. 25, 2003, andJapanese Patent Application Serial No. 2003-381189 filed on Nov. 11,2003. The foregoing applications are hereby incorporated herein byreference in their entirety.

TECHNICAL FIELD

The present invention relates to an optical recording medium and aninformation recording method. The present invention particularly relatesto an optical recording medium having a multi-layer structure recordinglayer portion including plural recording layers each having a track forguiding a recording light, and being adapted to record user data.

BACKGROUND ART

Recordable type DVDs (Digital Versatile Disk) include the DVD+R (DVDRecordable) and the DVD+RW (DVD Rewritable), for example. Suchrecordable type DVDs have high reproducing compatibility with aone-sided single layer read-only type DVD. Thus, much research anddevelopment are being conducted to increase the recording speed andrecording capacity of such recordable type disk media.

In an optical recording medium that has plural recording layers arrangedinto a multi-layer structure, a recording/reproducing light directed toa recording layer that is positioned far off with respect the incidencesurface of the recording/reproducing light passes through the recordinglayers positioned closer towards the incidence surface. Thus, in anoptical recording medium in which recording is realized by changing theoptical characteristics of a recording layer through changing therecording light intensity, the waveform condition and intensitycondition for the recording light differs depending on each recordinglayer. Also, in the case of successively realizing recording on pluralrecording layers, the waveform condition and the intensity condition forthe recording light changes from the initial conditions set at the startof the recording owing to heat generated during the recording of therecording information, for example. Thus, a waveform condition andintensity condition that differ from those for an optical recordingmedium with a single recording layer have to be set for a multi-layeroptical recording medium.

In response to the above considerations, for example, Japanese Laid-OpenPatent Publication No. 2002-50053 discloses providing unique informationof a data layer such as identification information of the data layer andrecording conditions for the data layer in a low reflectance region anda high reflectance region that are alternatingly arranged with respectto an extending direction of the recording tracks to realize a bar codelike arrangement.

However, the method disclosed in Japanese Laid-Open Patent PublicationNo. 2002-50053 is implemented under the premise that the uniqueinformation of a data layer may be read without conducting trackingservo, and thereby, an optical pickup may not be able to read the datalayer unique information through normal operations. Furthermore, theinformation region for the data layer unique information, namely, theportion corresponding to the bar code information region cannot be usedfor information recording, and thereby, recording information density issignificantly reduced.

SUMMARY OF THE INVENTION

It is a general object of the present invention to provide a new anduseful optical recording medium and information recording method thatcan solve the problems of the related art.

A more specific object of the present invention is to provide an opticalrecording medium that has a multi-layer structure with plural recordinglayers in which a recording condition suitable for each recording layermay be recognized through normal optical pickup operations to realize asuitable recording operation. Another object of the present invention isto provide an information recording method for recording information onsuch an optical recording medium.

It is also an object of the present invention to enable reading ofrecording conditions without receiving influence from a recording signalof a data region.

It is also an object of the present invention to enable reading ofrecording conditions while reducing excessive movement of the opticalpickup.

A more specific object of the present invention is to provide an opticalrecording medium having a multi-layer structure with plural recordinglayers each having tracks for guiding recording light, wherein user datamay be recorded on each recording layer, and information pertaining torecording conditions for the respective recording layers and layerinformation for identifying the respective layers are provided asinformation signals on the respective tracks. In the optical recordingmedium of the present invention (first optical recording medium), byproviding information pertaining to the recording conditions of therespective recording layers and the layer information for identifyingthe respective recording layers as information signals on the respectivetracks, recording conditions suitable for each recording layer may berecognized by normal operations of the optical pickup of following thetracks, and suitable recording operations can be realized.

A more specific object of the present invention is to provide an opticalrecording medium comprising:

a plurality of recording layers having tracks for guiding recordinglight that are arranged into a multi-layer structure, the recordinglayers being adapted to record user data;

wherein recording condition information and recording layeridentification information for the recording layers are provided on therecording layers as track information signals.

According to the optical recording medium of the present invention(first optical recording medium), the recording condition informationand recording layer identification information for the recording layersmay be provided as information signals on tracks (guide pits or guidancegrooves) so that a recording condition suitable for each recording layermay be recognized through normal optical pickup operations of followingthe tracks and desirable recording operations may be realized.

According to an embodiment of the present invention (second opticalrecording medium), the recording condition information and recordinglayer identification information may be preformatted on the tracks astrack information signals. Although the recording condition informationand recording layer identification information may be recorded as normalpits or recording marks, by preformatting the information on the tracksas track information signals, the information may be embedded withoutreducing a data region.

According to another embodiment of the present invention (third opticalrecording medium), the multi-layer structure recording layers mayalternatingly include a groove track and a land track as recordingpositions depending on whether the recording layers as odd numbered oreven numbered with respect to a layering order. According to the presentinvention, information may be recorded as tracks on the grooves, thelands, or both the groves and the lands of the multi-layer structurerecording layers as is the case in conventional arrangements; however,the present invention may also apply to a case in which the recordingpositions are alternatingly arranged to correspond to a groove track anda land track depending on whether the recording layers are odd numberedor even numbered.

According to another embodiment of the present invention (fourth opticalrecording medium), the recording condition information and recordinglayer identification information may be preformatted as pits or groovesthat form the tracks. By preformatting the recording conditioninformation and recording layer identification information as pits orgrooves that are formed on transparent substrates as tracks, the opticalrecording medium may be easily manufactured at a low cost.

According to another embodiment of the present invention (fifth opticalrecording medium), the recording condition information and recordinglayer identification information may be preformatted on the tracks astrack information signals through phase modulation. The recordingcondition information and recording layer identification information maybe recorded on the tracks through various methods such as periodicmodulation and amplitude modulation, for example; however, in the caseof a recording medium conforming to the DVD+R/RW standard having asynchronization signal with a high frequency of 100 kHz, phasemodulation is preferably used.

According to another embodiment of the present invention (sixth opticalrecording medium), the recording condition information may includeinformation pertaining to at least one of an intensity condition for therecording light and a light emission waveform condition for therecording light. The recording condition information may include variousconditions such as recording light intensity condition, wavelengthcondition, phase condition, wave surface condition, and light emissionwaveform condition. However, by using at least one of the recordinglight intensity condition and the light emission waveform condition, therecording condition may be easily adjusted by a single light emittingelement.

According to another embodiment of the present invention (seventhoptical recording medium), the recording condition information mayinclude information that directly designates a recording condition. Withthis arrangement, the recording condition may be easily and accuratelyset by simply reading the recording condition information.

According to another embodiment of the present invention (eighth opticalrecording medium), the recording condition information, may includeindirect information that designates a condition for deriving arecording condition. In this case, the recording condition may not beimmediately set by simply reading the recording condition information;however, the recording condition can be obtained from the derivingcondition, and the amount of information required may be reducedcompared to the direct recording condition information.

According to another embodiment of the present invention (ninth opticalrecording medium), the recording condition information and recordinglayer identification information may be positioned away from a dataregion of the tracks. The signal to noise ratio (SNR) of the signalsrecorded on the tracks changes when information is recorded on arecording layer, thereby, the recording position for recording therecording condition information is preferably located away from the dataregion, and in the case of a spiral or concentric track, the data regionis usually located at the middle diameter portion of, and thereby, therecording condition information is preferably recorded on at least oneof an inner diameter portion and an outer diameter portion.

According to another embodiment of the present invention (10th opticalrecording medium), the tracks are each arranged into a spiralconfiguration on the recording layers, the recording conditioninformation and recording layer identification information are providedat an inner diameter portion of the spiral configuration of acorresponding track if a spiraling direction of a recording operationfor the corresponding track is directed from an inner diameter side toan outer diameter side, and the recording condition information andrecording layer identification information are provided at an outerdiameter portion of the spiral configuration of a corresponding track ifa spiraling direction of a recording operation for the correspondingtrack is directed from the outer diameter side to the inner diameterside. Tracks of an optical recording medium often have spiralconfigurations, and by recording the recording condition information onthe inner diameter portion or the outer diameter portion depending onwhether the spiraling direction of the track extends from the innerdiameter side to the outer diameter side or vice versa, the recordingcondition information position may be arranged so that the opticalpickup may access the recording condition first upon initiating arecording operation with respect to a recording layer. Thereby, theoptical pickup may read the recording condition information and thenproceed directly to its recording operation without requiring excessmovement.

According to another embodiment of the present invention (11th opticalrecording medium), the tracks may each be arranged into a spiralconfiguration on the recording layers; a test writing region fordetermining a recording condition is provided at an inner diameterportion of the spiral configuration of a corresponding track if aspiraling direction of a recording operation for the corresponding trackis directed from an inner diameter side to an outer diameter side; and atest writing region is provided at an outer diameter portion of thespiral configuration of a corresponding track if a spiraling directionof a recording operation for the corresponding track is directed fromthe outer diameter side to the inner diameter side. Although testwriting is generally conducted to determine a recording condition, byproviding a test writing region on each of the recording layers, andarranging the test region to be positioned at the inner diameter portionor the outer diameter portion according to the spiraling direction ofthe tracks, the optical pick up may conduct the test writing and thenproceed directly to the recording operation without requiring excessmovement.

According to another embodiment of the present invention (12th opticalrecording medium), the respective recording condition information andrecording layer identification information for the recording layers maybe arranged to be recorded on the corresponding recording layers. Byproviding the recording condition information each individual recordinglayer, the recording condition of each recording layer may be accuratelyset, and the recording condition may be set for each recording layer.Thereby, even when a recording layer is added, the recording conditionformat may not have to be changed and may be expansively applied so thatcompatibility may be easily realized with a single-layer opticalrecording medium.

According to another embodiment of the present invention (13th opticalrecording medium), information that directly designates a recordingcondition is recorded as recording condition information on a firstrecording layer of the recording layers on which a recording is to beconducted first; and indirect information that designates a conditionfor deriving a recording condition based on the recording condition ofthe first recording layer is recorded as recording condition informationon a remaining second recording layer of the recording layers. In thiscase, the amount of information required for the recording informationmay be reduced in the second recording layer and onward compared to thecase of recording the recording condition information for eachindividual recording layer.

According to another embodiment of the present invention (14th opticalrecording medium), the recording condition information for all therecording layers may be recorded on a first recording layer of therecording layers on which a recording is to be conducted first. In thiscase, the recording condition information for all the recording layersmay be recorded on the first recording layer on which recording is to beconducted first so that from the second recording layer and onward, onlythe recording layer identification information may have to be read, andthe recording condition may not have to be read.

According to another embodiment of the present invention (15th opticalrecording medium), the recording condition information may includeinformation pertaining to a recording condition fluctuation with respectto a temperature or a recording light wavelength. In a multi-layeroptical recording medium, the amount of heat accumulated within arecording apparatus varies depending on whether recording isindividually conducted on each recording layer, or recording issuccessively conducted on all the recording layers, and in turn,environmental conditions such as the temperature may significantly vary.Particularly, in the case of using light emitting element such as alaser diode as a light source, there is likely to be a significantfluctuation in the wavelength depending on the temperature. In thisrespect, by including information pertaining to the recording conditionfluctuation with respect to the temperature or the recording lightwavelength, a suitable recording condition may be set according to thetemperature or wavelength variation.

According to another embodiment of the present invention (16th opticalrecording medium), a first recording layer of the recording layers onwhich a recording is to be conducted first may correspond to a recordinglayer of the recording layers that is positioned closest to a recordinglight incidence side. By arranging the first recording layer tocorrespond to the recording layer positioned closest to the recordinglight incidence side which receives the least influence from otherrecording layers, the recording condition may be appropriately read.

According to another embodiment of the present invention (17th opticalrecording medium), the first recording layer of the recording layers onwhich a recording is to be conducted first corresponds to a recordinglayer of the recording layers that is positioned farthest from arecording light incidence side. By arranging the first recording layerto correspond to the recording layer that is positioned farthest withrespect to the recording light incidence side, recording may beconducted on the closer recording layer(s) without receiving influencefrom the preceding recording layer(s) including the first recordinglayer, and thereby, stable recording may be realized.

According to another embodiment of the present invention (18th opticalrecording medium), the recording layers are adapted to be transmissivewith respect to a recording light wavelength and arranged on substrateshaving the tracks of the recording layers formed thereon. In this case,the optical recording medium of the present invention may be easilyprovided at a low cost.

According to another embodiment of the present invention (19th opticalrecording medium), the optical recording medium of the present inventionmay conform to a DVD+R standard, and the recording layers may bearranged into a one-sided dual layer configuration. Accordingly, thepresent invention may be suitably applied to recordable type opticalrecording medium conforming to the DVD+R standard and having a one-sideddual layer structure.

According to another embodiment of the present invention (20th opticalrecording medium), the optical recording medium of the present inventionmay conform to a DVD+RW standard, and the recording layers may bearranged into a one-sided dual layer configuration. Accordingly, thepresent invention may be suitably applied to recordable type opticalrecording medium conforming to the DVD+R standard and having a one-sideddual layer structure.

Another specific object of the present invention is to provide aninformation recording method for recording information on an opticalrecording medium including a plurality of recording layers having tracksfor guiding recording light that are arranged into a multi-layerstructure, the recording layers being adapted to record user data, andrecording condition information and recording layer identificationinformation for the recording layers being provided on the recordinglayers as track information signals, the method including:

a condition reading step of reading recording condition information andrecording layer identification information provided as track informationin the optical recording medium;

a recording condition setting step of setting a recording condition fora recording layer that is subject to recording based on the recordingcondition information and recording layer identification information forsaid recording layer that are read in the condition reading step; and

a recording operation execution step of executing a recording operationon the recording layer that is subject to recording according to therecording condition set in the recording condition setting step.

According to the information recording method of the present invention,even in a multi-layer optical recording medium having plural recordinglayers, recording condition information and recording layeridentification information for a recording layer provided as trackinformation may be read, and the recording condition for the recordinglayer may be set before executing a recording operation so that suitablerecording may be conducted according to a suitable recording conditionfor each recording layer.

Another specific object of the present invention is to provide anoptical recording medium, including:

a multi-layer structure recording layer portion including a plurality ofrecording layers having tracks for guiding recording light and beingadapted to record data;

wherein recording condition information and recording layeridentification information for the recording layers are recorded asinformation signals on the tracks of the recording layers.

According to the optical recording medium of the present invention,information such as recording condition information may be recognizedthrough normal optical pickup operations of following the track, andappropriate recordign may be realized.

Another object of the present invention is to provide a recording methodfor recording data on an optical recording medium having a multi-layerstructure recording layer portion that includes a plurality of recordinglayers having tracks for guiding a recording light and being adapted torecord data, where recording condition information and recording layeridentification information for the recording layers are recorded asinformation signals on the tracks of the recording layers, the recordingmethod including the steps of:

reading at least one of the information signals from the opticalrecording medium;

setting a recording condition for a recording layer that is subject torecording based on the read information signal; and

recording data on the recording layer that is subject to recordingaccording to the set recording condition.

According to the recording method of the present invention, suitablerecording may be conducted according to a suitable recording conditionfor each of the recording layers.

Further, other objects and features of the present invention aredescribed with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional diagram showing an optical recording mediumaccording to an embodiment of the present invention;

FIG. 2 is a diagram showing a first signal format of a guiding trench;

FIG. 3 is a diagram showing a second signal format of a guiding trench;

FIG. 4 is a diagram showing a third signal format of a guiding trench;

FIG. 5 is a diagram showing a fourth signal format of a guiding trench;

FIG. 6 is a diagram showing a comparison example of a signal format of aguiding trench;

FIG. 7 is a flowchart illustrating an information recording methodaccording to an embodiment of the present invention;

FIG. 8 is a cross-sectional diagram showing a modified example of anoptical recording medium that implements a different tracking scheme;

FIG. 9 is a diagram showing a wobble signal on the groove track of theoptical recording medium of FIG. 8; and

FIG. 10 is a diagram showing a wobble signal on a land track of theoptical recording medium of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, a description is given, with reference to thedrawings, of embodiments of the optical recording medium and informationrecording method of the present invention.

[Basic Structure of Optical Recording Medium]

According to one aspect, the present invention may be applied to anoptical recording medium having a multi-layer structure in which pluralrecording layers are layered with respect to the incidence direction ofa recording/reproducing light. FIG. 1 is a cross-sectional diagramshowing an optical recording medium according to an embodiment of thepresent invention. FIG. 1 shows a one-sided dual layer optical recordingmedium 1 in which recording/reproducing light is irradiated on onerecording side. The optical recording medium 1 includes a transparentsubstrate 2, a first recording layer 3, a second recording layer 4, anda transparent substrate 5 that are layered on top of each other in theabove order. The first recording layer 3 has a layer structure includinga recording film 6 that is formed on the transparent substrate 2 and areflection film 7 that is formed on the recording film 6. The secondrecording layer 4 has a layer structure including a reflection film 8that is formed on the transparent substrate 5 and a recording film 9that is formed on the reflection film 8. The first recording layer 3 andthe second recording layer 4 having the layer structures are bonded by abonding film 10.

In the following, each of the layers of the optical recording medium 1is described in greater detail.

First, for the recording films 6 and 9, a material that changes itsphysical form or optical characteristics due to thermal or opticalinfluences from irradiation of recording light is preferably used. Forexample, if the optical recording medium 1 corresponds to a recordabletype one-sided dual layer optical recording medium conforming to theDVD+R standard, and an organic dye material is used, metal complex dyessuch as azo dyes, cyanine dyes, phthalo cyanine dyes, pyrylium dyes,azulenium dyes, squarylium dyes, Ni, and Cr, or nephtoquinones,anthraquinone dyes, indophenol dyes, indoaniline dyes, triphenylmethanedyes, triarylmethane dyes, aminiums, diimmonium dyes, and formazan metalchelates. Particularly, azo dyes, squarylium dyes, formazan metalcheltaes that have good optical resistance characteristics are preferredorganic dye materials. Further, the organic dye material may include athird component such as a binder, or a stabilizer. As for the formationmethod of the organic dye material, the organic dye may be developed ina solvent and applied using the spin coating method, or sputtering invacuum may be conducted to form the film layer. The film thicknesses ofthe recording films 6 and 9 are preferably within a range of 300˜5000 Åand more preferably within a range of 700˜2000 Å. In the case where thespin coating method is used, annealing at a high temperature ispreferably performed in order to remove the residue solvent. Theannealing temperature is preferably within a range of 80˜110° C., andmore preferably around 100° C. The annealing time period is preferablywithin a range of 15˜30 minutes.

It is noted that in a case where the optical recording medium 1corresponds to a rewritable type one-sided dual layer optical recordingmedium conforming to the DVD+RW standard on which information isrecorded by changing the atomic arrangement of the recording layers, aphase change material may be used instead of an organic dye material. Inthis case, the recording films 6 and 9 include a film made of the phasechange material and a heat insulating film for maintaining the heat ofthe phase change material. As a specific example, the recording films 6and 9 may be made of a metal alloy represented asX_(A)—X_(B)—X_(C)—Ge—Te; wherein X_(A) may correspond to at least one ofthe following elements: Cu, Ag, Au, Sc, Y, Ti, Zr, V, Nb, Cr, Mo, Mn,Fe, Ru, Co, Rh, Ni, Pd, Hf, Ta, W, Ir, Pt, Hg, B, C, N, P, O, S, Se,lanthanide, actinide, alkaline earth metal, and inactive gas elements;X_(B) may correspond to at least one of the following elements: halogenelements such as Cl and I, and alkaline metal such as Na; and X_(C) maycorrespond to at least one of the following elements: Sb, SN, As, Pb,Bi, Zn, Cd, Si, Al, Ga, and In. Also, it is noted that metal materialssuch as metal elements Tb, Fe, and Co that are used as magneto-opticmaterials may be used in the recording films 6 and 9. The protectivefilms of the recording films 6 and 9 may be made of the same material orthey may be made of different materials. Specifically, each of theprotective films may be made of an oxide such as SiO, SiO₂, ZnO, SNO₂,Al₂O₃, TiO₂, In₂O₃, MgO, and ZrO₂; a nitride such as Si3N4, AlN, TiN,BN, and ZrN; a sulfide such asZnS, In2S3, and TaS4; a carbide such asSiC, TaC, B4C, Wc, TiC, and ZrC; a diamond-shaped carbon; or acombination of two or more of the above materials. As for the formationmethod of the protective films, sputtering, ion plating, vacuumdeposition, or plasma CVD, for example, may be used.

The reflection films 7 and 8 correspond to silver films formed throughsputtering, for example. As the material of the reflection films 7 and 8metal such as aluminum, silver, copper, or metal alloys containing theabove materials as their main component may be used. Particularly, metalor metal alloys containing gold as their main component may preferablybe used as the material of the reflection films 7 and 8. When silver ismainly used, the atomic concentration of silver is preferably within arange of 80˜100%, and more preferably within a range of 90˜100%. Also,aluminum may be used as the material of the reflection films 7 and 8since aluminum is inexpensive and is known to be used in compact disks(CD). In the case of using a metal or a metal alloy as the metal filmmaterial, the film may be formed using a vacuum film deposition methodsuch as sputtering or vacuum vapor deposition. In this case, a techniquemay be applied of changing the degree of vacuum within the vacuumchamber (e.g., approximately 10⁻⁵ torr) in performing sputtering to forma film that varies in density or crystallization states so that thereflectance of the film may be increased. In a case where at least onerecording layer is placed below the reflection film 7 and 8 with respectto the incident direction of the recording/reproducing light, thereflection films 7 and 8 need to be semi-transparent so as to allow thereflection light to pass through. Thereby, the film thicknesses of thereflection films 7 and 8 are preferably between 300 Å and 1000 Å.

The transparent substrates 2 and 5 corresponding to bases of therecording films 6 and 9 are preferably made of material that istransmissive with respect to the wavelength of the recording/reproducinglight. For example, plastic such as polycarbonate, acryl resin,polymetacrylate methyl, polystyrene resin, vinyl chloride resin, orepoxy resin; or glass may be used. It is noted, however, that othermaterials may also be used. Upon considering factors such as facility information, cost, and weight differences of the material, polycarbonateor acryl resin may preferably be used. With respect to each pair of therecording film 6 and the reflection film 7, and the recording film 9 andthe reflection film 8, the recording films 6 and 9 have to be positionedtoward the incidence direction of the recording/reproducing light.Thereby, the order of the recording films and the reflection films withrespect to the transparent substrates 2 and 5 is such that if theincident light passes through the transparent substrate to reach therecording layer, the transparent substrate 2, the recording film 6, andthe reflection film 7 are preferably arranged in this order. If theincident light does not pass through the transparent substrate to reachthe recording layer, the transparent substrate 5, the reflection film 8and the recording film 9 are preferably arranged in this order.

On the reflection films 7 and 8, guide trenches (or guide pits=pre-pits)11 and 12 corresponding to tracks for guiding the recording light areformed. As for their preferred formation method with regard tomanufacturing facility and costs, the guide trenches (or guide pits) 11and 12 may be formed on the transparent substrates 2 and 5 and thereflection films 7 and 8 may be formed thereon. In a case wheredetection is conducted based on interference caused by the pathdifference of the recording/reproducing light at the region of the guidetrenches (or guide pits) 11 and 12 and other regions, the depth of theguide trenches (or guide pits) 11 and 12 is preferably equal to λ/8n,where n represents the refractive index of the transparent substrates 2and 5, and λ represents the wavelength of the recording light.

The guide trenches (or guide pits) 11 and 12 for guiding the recordinglight are arranged to guide the recording light to accurately scan therecording region of the optical recording medium 1, and are generallyprovided with synchronization signals for enabling the recording lightto scan the optical recording medium at a designated line speed. In suchcase, the guide trenches 11 and 12 are generally wobbled atpredetermined intervals. In order to record information such asrecording condition information on the guide trenches (guide pits) 11and 12, the synchronization signals generated from the guide trenches(guide pits) 11 and 12 are preferably modulated through periodicmodulation, amplitude modulation, or phase modulation, for example. Inthe case of the optical recording medium 1 of the present embodiment,since there may be a wide variation in the intensity of the reflectionlight depending on the state of the optical recording medium 1, periodicmodulation and phase modulation are preferred rather than amplitudemodulation. Further, in the DVD+R/RW where the synchronization signalhas a high frequency of 100 kHz, phase modulation is preferred.

According to a preferred method of manufacturing the multi-layerstructure of the recording films 6 and 9, the recording films 6 and 9,and the reflection films 7 and 8 are formed on the transparent substrate2 and 5, after which the substrates 2 and 5 are bonded together. In suchcase, an adhesive sheet, a thermosetting adhesive, a UV cure adhesive,or a cationic UV cure adhesive may preferably be used as the bondingfilm 10. Particularly, to achieve smoothness and evenness in the bondingfilm 10, an adhesive sheet is preferably used as the bonding film 10.

In the optical recording medium 1 having a multi-layer structure withplural recording layers 3 and 4 that are formed according to theabove-described procedures, the recording layers 3 and 4 each havediffering environmental conditions such as optical conditions andthermal conditions of the incident recording light, and thereby, highquality recording cannot be realized on these recording layers using thesame recording condition. It is noted that the “optical conditions” maycorrespond to intensity change of the recording light that occurs whenthe recording light passes through the recording layer that ispositioned toward the recording light incidence surface (first recordinglayer 3) and reaches the recording layer that is positioned further awayfrom the recording light incidence surface (second recording layer 4), adifference in the optical path length from passing plural transparentsubstrates, and a phase change caused by birefringence of thetransparent substrate 2. Also, the “thermal conditions” may correspondto heat accumulation and heat emission conditions of the recording layer3 and 4 depending on the positioning and thickness differences of therecording films 6 and 9, the reflection films 7 and 8, the transparentsubstrates 2 and 5, and the bonding film 10.

By selecting suitable recording conditions for each of the recordinglayers 3 and 4 according to the differences in the environmentalconditions of the recording layers 3 and 4, high quality recording onplural recording layers 3 and 4 may be realized. The recordingconditions may include the intensity, wavelength, phase, wave surface,light emission waveform of the recording light, for example. It is notedthat the intensity condition and the light emission waveform conditionare preferably used since such conditions may be easily adjusted using asingle light emitting element.

The recording condition information content may correspond to a directcondition such as a numerical value designating the intensity or thewaveform of the recording light, or an indirect condition such as acondition for deriving a recording condition through test writing on theoptical recording medium 1 or based on the reflectance fluctuation ofthe optical recording medium 1. As an exemplary method for deriving arecording condition, the β method used in a CD-R or a DVD±R, or the γmethod used in a CD-RW or a DVD+RW to derive an intensity condition forthe recording light may be used. In this case, β or γ, which correspondsto a target, and an approximate recording intensity for use in thecondition derivation process are included as the recording conditioninformation content. In another example, test writing may besuccessively performed while changing the waveform condition to obtain asuitable waveform condition. In yet another example, the thickness ofthe recording film and the transmittance of the transparent substratemay be estimated from a change in reflectance, and a suitable recordingcondition may be obtained accordingly. By using the above exemplarymethods of deriving a recording condition, the physical differences ofthe recording layers within the optical recording medium 1 are takeninto account, and the amount of information to be recorded as recordingcondition information on the guide trenches (or guide pits) 11 and 12corresponding to tracks may be reduced.

In the optical recording medium 1 having plural recording layers 3 and4, if a suitable recording condition is to be derived by conducting testwriting, it is preferred that a test writing region be provided on eachof the recording layers 3 and 4. Also, by conducting the test writingfor all the recording layers 3 and 4 at the beginning of a recordingoperation to derive a suitable recording condition for each of therecording layers 3 and 4, the test writing time required duringrecording may be reduced in successively recording on the recordinglayers 3 and 4. However, optical conditions such as the wavelength andefficiency of the light emitting element may change due to environmentalcondition changes such as a change in temperature during recording, andin turn, the suitable recording condition at the time of the actualrecording may differ from that determined at the beginning of therecording operation. Thereby, information pertaining to sensitivityfluctuation of each of the recording films 6 and 9 with respect towavelength and/or temperature may be included in the recording conditioninformation, and a condition calculated based on the sensitivityfluctuation of the recording films 6 and 9 caused by a change in anenvironmental condition such as the temperature may be supplemented tothe recording condition derived at the beginning of the recordingoperation so that a suitable recording condition for each of therecording layers 3 and 4 may be obtained at the beginning of therecording operation.

It is noted that the signal to noise ratio (SNR) of the signal of theguide trenches (guide pits) 11 and 12 corresponding to tracks changesafter information is recorded on the recording layers 3 and 4. Thereby,the recording positions of the recording condition information for therecording layers 3 and 4 that are to be recorded on the guide trenches(guide pits) 11 and 12 of the optical recording medium 1 are preferablylocated away from data regions on which arbitrary information may berecorded by a user. In a case where the guide trenches (guide pits) 11and 12 are arranged into concentric configurations or spiralconfigurations, the data region is usually located at a mid-diameterportion of the trench, and thereby, the recording condition informationis preferably recorded on at least one of an inner diameter portion oran outer diameter portion of the trench.

Further, in a case where the guide trench (guide pits) 11 and 12 arearranged into a spiral configuration, the entire surface of the opticalrecording medium 1 may be successively scanned when the opticalrecording medium 1 is rotated for recording/playback. In this case, inorder to eliminate excess movement of the optical pickup at thebeginning of a recording operation, the recording condition informationis preferably recorded at the position at which the optical pickupstarts its recording operation for the corresponding recording layer(i.e., the inner diameter portion or the outer diameter portion).Specifically, the recording condition information is preferably recordedat the inner diameter portion if the spiraling direction with respect tothe rotation direction of the optical recording medium 1 forrecording/playback runs from the inner diameter side to the outerdiameter side, and the recording condition information is preferablyrecorded at the outer diameter portion if the spiraling direction runsfrom the outer diameter side to the inner diameter side.

Also, by determining the recording conditions through conducting testwriting on the optical recording medium 1, suitable recording conditionsfor the recording layers 3 and 4 that take into account environmentalconditions such as temperature and humidity may be derived. In suchcase, the test writing region is preferably provided at a position atwhich the optical pickup starts its recording operation for thecorresponding recording layer (i.e., inner diameter portion or outerdiameter portion) so as to obtain a good recording quality from thebeginning of the recording operation. Specifically, the test writingregion is preferably located at the inner diameter portion if the spiraldirection with respect to the rotation direction of the opticalrecording medium 1 for recording/playback is directed towards the outerdiameter portion, and the test writing region is preferably located atthe outer diameter portion if the spiral direction is directed towardsthe inner diameter portion. In this way, excess movement of the opticalpickup may be reduced and the operation time from test writing torecording may be reduced so that the recording may not be greatlyinfluenced by a fluctuation of the suitable recording condition with theelapse of time.

In one example of recording the recording conditions on the recordinglayers 3 and 4, recording conditions of the same specification may berecorded on the recording layers 3 and 4. In such case, a recordingcondition and/or a condition for deriving a recording condition may beset for each of the recording layers 3 and 4. In this example, when thenumber of recording layers is increased, the recording condition formatmay not have to be changes and may instead be extended. Thereby, thepresent embodiment may be applied to optical recording media such as theDVD±R/RW or the CD-R/RW which have already become widespeard as opticalrecording media with a single recording layer.

In another example of recording the recording conditions on therecording layers 3 and 4, a recording condition may be recorded on afirst recording layer on which recording is to be conducted first (i.e.,recording layer 3), and information for identifying the recording layer3 may be recorded on the reflection film 7 that is paired with therecording layer 3. On the other hand, information for deriving arecording condition for the other recording layer 4 based on therecording condition for the first recording layer 3 is recorded on therecording layer 4. By using this method, the amount of information to berecorded as recording condition information may be reduced in the secondrecording layer 4 and onward. Thus, by adding surplus signals to improvethe error correction performance, sufficient reading performance may bemaintained even when the SNR decreases compared to that at the time ofrecording on the first recording layer.

In yet another example of recording the recording conditions on therecording layers 3 and 4, the recording conditions for all the recordinglayers 3 and 4, may be recorded on the first recording layer 3. In thisexample, maintaining compatibility with a single recording layer opticalrecording medium becomes difficult; however, a recording condition maynot have to be read from the second recording layer 4 and onward so thatthe recording layer 4 may merely require a signal quality that issufficient for reading the identification signal of the recording layer4. It is noted that the first recording layer 3 on which recording is tobe conducted first preferably corresponds to a recording layer that ispositioned closest to the recording light incidence surface so that itreceives little influence from other recording layers such as therecording layer 4. Alternatively, the first recording layer 3 on whichrecording is performed first may correspond to a recording layer that ispositioned farthest from the incidence surface of the recording light.When the first recording layer 3 to be recorded first corresponds to therecording layer that is positioned farthest from the incidence surfaceof the recording light, recording on the second recording layer 4 may berealized without receiving influence from the preceding recording layersincluding the first recording layer 3 so that stable recording may berealized.

Further, in the optical recording medium 1 having plural recordinglayers 3 and 4, the amount of heat accumulated within an opticalrecording apparatus differs depending on whether recording is separatelyperformed on each recording layer 3 and 4, or recording is successivelyperformed on the recording layers 3 and 4. Accordingly, environmentalconditions such as temperature may vary significantly. Particularly,when a laser diode is used as the light source, variations in thewavelength with respect to temperature occur. Thereby, in such case therecording condition information of the optical recording medium 1preferably includes information pertaining to fluctuations of therecording conditions with respect to the temperature and the wavelength,for example. In this way, suitable recording may be realized regardlessof the position on the optical recording medium 1 at which the recordingis started.

[Signal Format]

In the following, specific examples of suitable signal formats invarious configurations of the optical recording medium 1 are describedwith reference to FIGS. 2˜5.

FIGS. 2˜5 respectively represent first through fourth signal formatsthat are recorded on the recording guide trenches (tracks) 11 and 12 ofthe optical recording medium 1. FIG. 6 shows a signal format recorded ona guide trench of an optical recording medium having a single layerstructure as a comparison example. In FIGS. 2˜5, “standard information”refers to the corresponding standard of the optical recording medium 1.“Disk (or medium) configuration” refers to information that may includephysical configuration information such as the size of the opticalrecording medium 1 and the track pitch of the guide trenches 11 and 12,the material of the recording layer, information pertaining to the startaddress and end address of the data region, and information pertainingto usage of the optical recording medium 1, for example. “Recordinglayer number” refers to the layer information for identifying each ofthe recording layers 3 and 4 by assigning differing values to therecording layers 3 and 4. “Vendor information” refers to vendor(manufacturer) identification information of the optical recordingmedium. “Version information” refers to the manufacture versioninformation of the optical recording medium 1. “Waveform condition”describes the sensitivity fluctuation of the recording film with respectto the waveform. It is noted that portions of the signal format shown inFIG. 6 that correspond to portions of the signal format of FIGS. 2˜5 aregiven the same description references.

[First Signal Format]

The first signal format shown in FIG. 2 is implemented in an opticalrecording medium 1 that uses the Parallel Track Path (PTP) method inwhich the first recording layer 3 and the second recording layer 4respectively have spiral guide trenches 11 and 12 that are directed fromthe inner diameter portion to the outer diameter portion of the medium.In this case, on each of the guide trenches 11 and 12 of the firstrecording layer 3 and the second recording layer 4, informationpertaining to a recording condition and layer information arepreformatted at the inner diameter portion.

Thereby, to conduct recording on the first recording layer 3, recordingcondition information preformatted on the guide trench 11 of the firstrecording layer 3 is used to conduct test writing on the first recordinglayer 3 to derive a suitable recording condition, and recording isperformed on the first recording layer 3 based on a direct recordingcondition. To conduct recording on the second recording layer 4, theoptical pickup moves to the inner diameter portion of the opticalrecording medium 1, and the recording condition information preformattedon the guide trench 12 of the second recording layer 4 is used toconduct test writing to derive a suitable recording condition, and torealize recording based on a direct recording condition. By using suchan optical recording medium 1, recording may be performed based on asuitable recording condition for each of the recording layers 3 and 4.

[Second Signal Format]

The second signal format shown in FIG. 3 is implemented in an opticalrecording medium 1 that uses the Opposite Track Path (OTP) method inwhich the first recording layer 3 has a spiral guide trench 11 that isdirected from the inner diameter portion to the outer diameter portionof the medium, and the second recording layer 4 has a spiral guidetrench 12 that is directed from the outer diameter portion to the innerdiameter portion of the medium. In this case, information pertaining toa recording condition and layer information are preformatted on theinner diameter portion of the guide trench 11 of the first recordinglayer 3, and information pertaining to a recording condition and layerinformation are preformatted on the outer diameter portion guide trench12 of the second recording layer 4.

Accordingly, recording condition information on the first recordinglayer 3 is used to conduct test writing on the first recording layer 3to obtain a suitable recording condition, and direct recording isperformed on the first recording layer 3 based on a direct recordingcondition. Then, to conduct recording on the second recording layer 4,the optical pickup that has moved to the outer diameter portion of themedium uses the recording condition information on the second recordinglayer 4 to conduct test writing on the outer diameter portion of thesecond recording layer 4 to obtain a suitable recording condition, anddirect recording is performed on the second recording layer 4 based on adirect recording condition.

By using an optical recording medium 1 having such a configuration, themoving distance of the optical pickup from the first recording layer 3to the second recording layer 4 may be reduced so that substantiallycontinuous recording may be realized and recording based on a suitablerecording condition may be performed on each of the recording layers 3and 4. Also, the signal format recorded on the guide trench 11 of thefirst recording layer 3 is substantially identical to the comparisonexample shown in FIG. 6 for a single-layer recording layer, and thereby,high downward compatibility may be achieved in the optical recordingmedium 1 according to this configuration.

[Third Signal Format]

The third signal format shown in FIG. 4 is implemented in an opticalrecording medium 1 similar to that for the second signal format thatuses the Opposite Track Path (OTP) method. However, unlike the secondsignal format, in the third signal format, indirect recording conditioninformation for deriving a recording condition for the second recordinglayer 4 based on a recording condition for the first recording layer 3is recorded on the guide trench 12 of the second recording layer 4 asinformation pertaining to a recording condition of the second recordinglayer 4. In this way, the amount of information required as recordingcondition information may be reduced compared to the second signalformat.

Accordingly, as in the first and second signal formats, the recordingcondition of the first recording layer 3 is used to conduct test writingon the first recording layer 3 to obtain a suitable recording condition,and direct recording on the first recording layer 3 is performed basedon a direct recording condition. Then, to conduct recording on thesecond recording layer 4, the optical pickup that has moved to the outerdiameter portion of the medium uses the recording condition recorded onthe second recording layer 4 to conduct test writing on the outerdiameter portion of the second recording layer 4 to derive a suitablerecording condition, and recording is conducted on the second recordinglayer 4 according to the recording condition of the second recordinglayer 4 that is derived from the recording condition of the firstrecording layer 3 based on the derivation information.

By using an optical recording medium having such a configuration, themoving distance of the optical pickup from the first recording layer 3to the second recording layer 4 may be reduced so that substantiallycontinuous recording may be realized and recording based on a suitablerecording condition may be conducted on each of the recording layers 3and 4. Also, it is noted that the signal format recorded on the guidetrench 11 of the first recording layer 3 is substantially identical tothe signal format shown in the comparison example of FIG. 6 for thesingle-layer recording layer, and high downward compatibility may beachieved in the optical recording medium 1. Further, since the recordingcondition of the second recording layer 4 merely includes a conditionfor modifying the recording condition of the first recording layer 3,the amount of information of the recording condition for the secondrecording layer may be reduced.

[Fourth Signal Format]

The fourth signal format shown in FIG. 5 may be implemented in anoptical recording medium 1 similar to that for the second and thirdsignal formats that uses the Opposite Track Path (OTP) method. However,unlike the second and third signal formats, in the fourth signal format,all information items pertaining to recording conditions for therecording layers 3 and 4 are recorded on the guide trench 11 of thefirst recording layer 3, while layer information is still recorded oneach of the recording layers 3 and 4.

Accordingly, recording on the first recording layer 3 is conducted in amanner similar to that used in the first through third signal formats.That is, the recording condition for the first recording layer 3 that isrecorded on the first recording layer 3 is used to conduct test writingon the first recording layer 3 to derive a suitable recording condition,and direct recording is performed on the first recording layer 3 basedon a direct recording condition. Then, to conduct recording on thesecond recording layer 4, the optical pickup that has moved to the outerdiameter portion of the medium recognizes the layer information recordedon the second recording layer 4, and uses the recording condition forthe second recording layer 4 that is read from the first recording layer3 to conduct test writing on the outer diameter portion of the secondrecording layer 4 to derive a suitable recording condition, andrecording is conducted on the second recording layer 4 based on thederived recording condition.

By using an optical recording medium 1 having such a configuration, themoving distance of the optical pickup from the first recording layer 3to the second recording layer 4 may be reduced so that substantiallycontinuous recording may be realized and recording may be conductedunder a suitable recording condition for each of the recording layers 3and 4. Also, since the recording condition for the second recordinglayer 4 is recorded on the first recording layer 3, recording on thesecond recording layer 4 may be realized by simply recognizing the layerinformation for identifying the second recording layer 4.

[Information Recording Method]

A schematic process as is illustrated in FIG. 7 may be used as aninformation recording method in a case where any one of the opticalrecording media 1 implementing the above-described first through fourthsignal formats is loaded in an optical information recording apparatus.FIG. 7 is a flowchart illustrating an information recording methodaccording to an embodiment of the present invention.

According to FIG. 7, first, in step S1, a determination is made as towhether an optical recording medium is loaded. When an optical recordingmedium 1 is loaded and a positive determination (YES) is made in stepS1, the following steps are undertaken before conducting a recordingoperation on the optical recording medium 1. In step S2 (conditionreading step), information pertaining to a recording condition and layerinformation for identifying the recording layer 3/4 are read from theguide trench 11/12 of the optical recording medium 1. Then, in step S3(recording condition setting step), based on the information pertainingto a recording condition and layer information for identifying therecording layer 3/4 that are read in step S2, a recording condition isset for the recording layer 3/4 that is subject to a recordingoperation. Then, in step S4 (recording operation execution step), a datarecording operation is conducted to record user data, for example, onthe recording layer 3/4 that is subject to the recording operationaccording to the recording condition set in step S3.

According to the present embodiment, even with an optical recordingmedium 1 having a multi-layer structure with plural recording layers 3and 4, information pertaining to a recording condition and layerinformation for identifying each of the recording layers that arerecorded on the guide trenches 11 and 12 may be read and recordingconditions for the recording layer 3 or 4 may be set to conduct a datarecording operation. Thereby, recording under a suitable recordingcondition may be realized on each of the recording layers 3 and 4.

[Modification Example]

In the above descriptions of recording information on the multi-layeredrecording layers 3 and 4, the track format is described as implementinga conventional format of recording on the grooves (guide trenches 11 and12) of the recording layers 3 and 4 (identical results may be obtainedby a format of recording on lands or both the grooves and lands of therecording layers). However, other formats may be used such as a formatof alternatingly setting a groove track and a land track as recordingpositions of the multi-layer recording layers depending on whether therecording layer corresponds to an odd numbered layer or an even numberedlayer. For example, a groove track may be set as the recording positionwith respect to the first recording layer and its wobble, and a landtrack may be set as the recording position with respect to the secondrecording layer and its wobble. In conducting recording on the secondrecording layer of a dual-layer recording medium that uses an organicdye material as its main material, a relatively deep mark with respectto a layer depth direction has to be formed on the second recordinglayer. However, when a mark with such depth is formed on the secondrecording layer, heat generated upon conducting the recording is likelyto penetrate to the land side owing to structural reasons so thatdegradation occurs in the recording quality. Thereby, the track formatdescribed above may be used to avoid such inconvenience.

In the following, this track format is described with reference to FIG.8. FIG. 8 is a cross-sectional diagram showing a configuration of anoptical recording medium according to a modification example thatimplements the above-described track format. It is noted that in FIG. 8,elements that are identical to those shown in FIG. 1 are given the samenumerical references and their descriptions are omitted. Also, therecording/reproducing light is indicated by a one-dot-dashed line inthis drawing.

Referring to FIG. 8, on the first recording layer 3, a recording film 6having a trench structure in the light irradiation direction is formedwith respect to the reflection layer 7, and on the second recordinglayer 4, a recording film 9 having a trench structure in the lightirradiation direction is formed with respect to the reflection layer 8.In a case where the optical recording medium 1 corresponds to a diskmedium, the trench structure is formed into a spiral path that startsfrom the center of the disk medium and is directed towards the outerdiameter side, and an information recording/playback apparatus followsthis trench to conduct playback and recording of information. Generally,the trench that is positioned closer to the incidence surface of the ofthe recording/reproducing light is referred to as a groove track 11, andthe trench that is positioned further away from the incidence surface isreferred to as a land track 13. On the first recording layer 3, therecording film 6 is formed on the groove track 11, and on the secondrecording layer 4, the recording film 9 is formed on the land track 13.In other words, the recording films of the first recording layer 3 andthe second recording layer 4 are respectively formed as tracks havingdiffering configurations.

More specifically, in the trench structure of the first recording layer3, the groove track 11 is formed by the recording film 6. The groovetrack 11 is wobbled as is shown in FIG. 9, and the wobble signalprovided on the groove track 11 may include position information withinthe medium (disk) plane and recording power and recording pulse form forconducting OPC, for example. FIG. 9 illustrates the wobble signal on thegroove track of the optical recording medium shown in FIG. 8.

The second recording layer 4 is formed over the first recording layer 3with a bonding layer 10 and/or an inorganic protective layer 14 placedin between. Unlike the first recording layer 3, the recording film 9 ofthe recording layer 4 is formed on the land track 13, and the wobblesignal is also recorded on the land track 13 as is shown in FIG. 10.FIG. 10 shows a wobble signal on the land track of the optical recordingmedium shown in FIG. 8. This wobble signal may include positioninformation of the second recording layer 4, and the recording power andrecording pulse form for conducting OPC, for example.

Even in an optical recording medium implementing a track format asdescribed above, the first through fourth signal formats illustrated inFIGS. 2˜5 may be implemented, and recording according to a suitablerecording condition may be conducted for each of the recording layers 3and 4.

It is noted that in FIGS. 9 and 10, waveforms of tracking error signals(TE) for the groove track 11 and the land track 13 are respectivelyshown at the bottom section of the drawings as references.

It is further noted that the optical recording medium according to thepresent invention is not limited to a disk medium. In fact, the presentinvention may also be applied to other various types of opticalrecording media.

Also, the present invention is not limited to the preferred embodimentsdescribed above, and various modifications and changes may be madewithout departing from the scope of the present invention.

1. An optical recording medium comprising: a plurality of recordinglayers having tracks for guiding recording light that are arranged intoa multi-layer structure, the recording layers being adapted to recorduser data; wherein recording power and recording pulse form informationfor the recording layers is provided on the recording layers as trackinformation signals.
 2. The optical recording medium as claimed in claim1, wherein the recording power and recording pulse form information ispreformatted on the tracks.
 3. The optical recording medium as claimedin claim 2, wherein the multi-layer structure recording layers alternatebetween a groove track and a land track as recording positions accordingto a layering order of the recording layers.
 4. The optical recordingmedium as claimed in claim 2, wherein the recording power and recordingpulse form information is preformatted as pits or grooves that form thetracks.
 5. The optical recording medium as claimed in claim 2, whereinthe recording power and recording pulse form information is preformattedon the tracks through phase modulation.
 6. The optical recording mediumas claimed in claim 1, wherein the recording power information includesinformation pertaining to at least one of an intensity condition for therecording light and a light emission waveform condition for therecording light.
 7. The optical recording medium as claimed in claim 1,wherein the recording power and recording pulse form informationincludes information that directly designates a recording condition. 8.The optical recording medium as claimed in claim 1, wherein therecording power and recording pulse form information is positioned awayfrom a data region of the tracks.
 9. The optical recording medium asclaimed in claim 1, wherein the respective recording power and recordingpulse form information for the recording layers are arranged to berecorded on the corresponding recording layers.
 10. The opticalrecording medium as claimed in claim 1, wherein: information thatdirectly designates a recording condition is recorded as recordingcondition information on a first recording layer of the recording layerson which a recording is to be conducted first; and information thatdesignates a condition for deriving a recording condition based on therecording condition of the first recording layer is recorded asrecording condition information on a remaining second recording layer ofthe recording layers.
 11. The optical recording medium as claimed inclaim 1, wherein the recording power and recording pulse forminformation for all the recording layers are recorded on a firstrecording layer of the recording layers on which a recording is to beconducted first.
 12. The optical recording medium as claimed in claim 1,wherein a first recording layer of the recording layers on which arecording is to be conducted first corresponds to a recording layer ofthe recording layers that is positioned closest to a recording lightincidence side.
 13. The optical recording medium as claimed in claim 1,wherein a first recording layer of the recording layers on which arecording is to be conducted first corresponds to a recording layer ofthe recording layers that is positioned farthest from a recording lightincidence side.
 14. An information recording method for recordinginformation on an optical recording medium including a plurality ofrecording layers having tracks for guiding recording light that arearranged into a multi-layer structure, the recording layers beingadapted to record user data, and recording power and recording pulseform information for the recording layers being provided on therecording layers as track information signals, the method comprising: acondition reading step of reading recording power and recording pulseform information provided as track information in the optical recordingmedium; a recording condition setting step of setting a recordingcondition for a recording layer that is subject to recording based onthe recording power and recording pulse form information for saidrecording layer that are read in the condition reading step; and arecording operation execution step of executing a recording operation onthe recording layer that is subject to recording according to therecording condition set in the recording condition setting step.
 15. Anoptical recording medium, comprising: a multi-layer structure recordinglayer portion including a plurality of recording layers having tracksfor guiding recording light and being adapted to record data; whereinrecording power and recording pulse form information for the recordinglayers are recorded as information signals on the tracks of therecording layers.
 16. The optical recording medium as claimed in claim15, wherein the information signals are preformatted as pits or groovesthat form the tracks.
 17. The optical recording medium as claimed inclaim 15, wherein the information signals are preformatted on the tracksthrough phase modulation.
 18. The optical recording medium as claimed inclaim 15, that has a disk configuration, wherein the information signalsare recorded on an inner diameter region or an outer diameter region ofthe disk configuration.
 19. The optical recording medium as claimed inclaim 15, wherein an information signal that is recorded on a firstrecording layer of the recording layers on which data are to be recordedfirst includes the recording condition information for all the recordinglayers.
 20. A recording method for recording data on an opticalrecording medium having a multi-layer structure recording layer portionthat includes a plurality of recording layers having tracks for guidinga recording light and being adapted to record data, where recordingpower and recording pulse form information for the recording layers arerecorded as information signals on the tracks of the recording layers,the recording method comprising the steps of: reading at least one ofthe information signals from the optical recording medium; setting arecording condition for a recording layer that is subject to recordingbased on the read information signal; and recording data on therecording layer that is subject to recording according to the setrecording condition.
 21. The recording method as claimed in claim 20,wherein: the optical recording medium has a disk configuration; and thestep of setting the recording condition includes conducting test writingon an inner diameter region or an outer diameter region of the diskconfiguration.
 22. The recording method as claimed in claim 20, whereinthe step of setting the recording power and recording pulse formincludes conducting test writing on the recording layer subject torecording using the recording power and recording pulse form informationof the information signals recorded on said recording layer, andderiving an optimal recording condition for said recording layer basedon a result of the test writing.